U  D 


No.   1919 


DESCRIPTION 


OF  THE 


Coifs  Double-Action  Revolver 

CALIBER  ,38 

WITH  RULES  FOR  MANAGEMENT,  MEMORANDA 
OF  TRAJECTORY,  AND  DESCRIP- 
TION OF  AMMUNITION 


{FOUR  PLATES) 


APRIL  1,  1905 
REVISED  OCTOBER  3,  1908 
REVISED  JUNE  19,  1917 


WASHINGTON 
GOVERNMENT  PRINTING  OFFICE 

1917 


No.   1919 


ij.  S.  Cv<?<  V^cr  nee.      dep'T*' 

DESCRIPTION 

OF  THE 

Coifs  Double-Action  Revolver 

CALIBER  .38 

WITH  ^  RULES  FOR  MANAGEMENT,  MEMORANDA 
^OF  TRAJECTORY.  AND  DESCRIP- 
TION OF  AMMUNITION 


{FOUR  PLATES) 


APRIL  1,  1905 
REVISED  OCTOBER  3,  1908 
REVISED  JUNE  19,  1917 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 

1917 


\3 


--m 


(Form  No.  1919.) 
THE  OFFICIAL  NUMBER  OF  THIS  COPY 


The  Commanding  Officer  or  the  Post  or  Coast  Defense 
Ordnance  Officer  to  whom  this  copy  is  issued  will  be 
held  personally  responsible  for  its  safe=keeping.  When 
another  officer  relieves  him  a  receipt  for  it  by  number 
will  be  taken,  which  should  be  mailed  to  the  CHIEF  OF 
ORDNANCE,  U.  S.  Army,  Washington,  D.  C. 


m= 


m 


NOTE. — This  pamphlet  may  be  destroyed  when  super- 
seded by  one  of  later  date. 

(2) 


War  Department, 
Office  of  the  Chief  of  Ordnance, 

Washington,  June  19,  1917. 
This  manual  is  published  for  the  information  and  government  of  the  Regular  Army 
and  National  Guard  of  the  United  States. 
By  order  of  the  Secretary  of  War:  * 

William  Crozier, 
Brigadier  General,  Chief  of  Ordnance. 
(3) 

105405—17 


3G5267 


CONTENTS. 


Pagn. 

Ammunition 14-15 

Component  parts 5 

Different  models  in  service 5 

Dimensions 11 

Exterior  ballistics 11-13 

Important  points 10 

Operation  of  the  parts.  - 6-8 

Parts  issued  for  repairs 9-10 

Parts  not  issued 10 

To  dismount  and  assemble 8 

To  eject  the  shells  and  load 8 

(4) 


DESCRIPTION  OF  COLT'S  DOUBLE-ACTION  REVOLVER, 

CALIBER  .38. 


(4  PLATES.) 


DIFFERENT  MODELS  IN   SERVICE. 

The  Colt's  double-action  revolvers,  caliber  .38,  in  service  are 
marked  Army, models  1894,  1896,  1901,  and  1903.  The  first  model 
issued  was  that  of  1892,  but  all  the  revolvers  of  that  model  were 
altered  into  model  of  1894  by  the  addition  of  the  locking  lever,  which 
is  pivoted  by  its  screw  in  a  recess  in  the  left  side  of  the  frame  and 
prevents  the  hanomer  being  cocked  until  the  cyUnder  is  positively 
closed  and  locked.  The  models  of  1894  and  1896  are  identical.  The 
model  of  1901  differs  from  the  previous  models  in  having  the  hntt 
swivel  for  lanyard.  The  model  of  1903  differs  from  the  model  of  1901 
in  having  the  diameter  of  the  bore  reduced  to  insure  better  accu- 
racy and  in  having  a  smaller  and  better-shaped  handle.  The  model 
of  1901  revolvers  last  made  have  the  thinner  stocks 

COMPONENT   PARTS. 

Part  I,  Class  VII,  Section  2. 
Crane  bushing. 
Crane  lock. 
Crane-lock  screw. 
Cylinder  and  ejector,  assembled. 
Cylinder  bolt  with  spring,  assembled. 
Cylinder- bolt  spring. 
Ejector  rod. 
Ejector-rod  head. 
Ejector  spring. 

Gauge  for  space  between  cy Under  and  barrel. 
Hammer  with  strut,  strut  pin,  and  strut  spring,  assembled. 
Hammer  pin. 
Hammer  stirrup. 
Hammer-stirrup  pin. 
Hammer-strut  spring. 
Hand  and  spring,  assembled. 
Hand  spring. 
Latch  pin. 
Latch  spring. 
Locking  lever. 
Locking-lever  screw. 
Mainspring. 

Mainspring  tension  screw. 
Punch  and  set  for  replacing  recoil  plates. 

(5) 


Range  rod  for  testing  alignment  of  the  barrel  and  chambers  of  cylinder. 

Rebound  lever. 

Rebound-lever  pin. 

Rebound-lever  spring. 

Rebound-lever-spring  pin. 

Recoil  plate. 

Screw  driver. 

Side-plate  screw. 

Stock,  right  ^  (model  of  1901  or  model  of  1903). 

Stock,  left  ^  (model  of  1901  or  model  of  1903). 

Stock  pin. 

Stock  screw. 

Trigger  (includes  rebound-lever  arm  pin). 

Trigger  pin. 

OPERATION  OF  THE  PARTS. 

Plate  I  is  a  side  view  of  the  revolver. 

Plate  II  shows  the  revolver  with  the  side  plate  and  stock  removed, 
and  with  cyhnder  and  other  parts  cross-sectioned  to  show  construc- 
tion. 

Plate  III  shows  the  component  parts  except  the  barrel,  sight,  and 
frame. 

In  the  plates,  parts  are  given  the  same  numbers  as  in  the  list  of 
component  parts  and  in  the  description  that  follows. 

The  barrel  (1)  is  firmly  screwed  to  the  frame  (17).  Until  the 
adoption  of  the  model  1903  the  exact  diameter  of  the  bore  was  0.363 
inch.  It  is  now  0.357  inch,  and  all  new  barrels  used  in  the  repair  of 
revolvers  of  whatever  model  are  of  this  size.  The  front  sight  (42)  is 
brazed  on  the  barrel.  The  rear  sight  is  merely  a  longitudinal  groove 
in  the  upper  surface  of  the  frame. 

The  lock  mechanism  is  contained  in  the  frame  and  consists  of  the 
hammer  (18)  with  its  stirrup  (20),  stirrup  pin  (21),  strut  (22),  strut 
pin  (23),  and  strut  spring  (24) ;  the  trigger  (47)  with  its  pin  (48) ;  the 
rebound  lever  (34)  with  its  spring  (37) ;  the  hand  (25)  with  its  spring 
(26) ;  the  cylinder  bolt  (9)  with  its  spring  (10) ;  the  locking  lever  (30) ; 
and  the  mainspring  (32) . 

The  hammer  (18),  trigger  (47),  and  rebound  lever  (34)  are  pivoted 
on  their  respective  pins,  which  are  fastened  in  the  left  side  of  the 
frame  (17).  The  lower  end  of  the  mainspring  (32)  fits  into  a  slot  in 
the  frame  and  its  upper  end  engages  the  hammer  stirrup  (20) .  The 
mainspring  tension  screw  (33)  regulates  the  intensity  of  the  blow  of 
the  hammer. 

The  lower  end  of  the  rebound-lever  spring  (37)  is  secured  to  the 
frame  by  the  rebound-lever-spring  pin  (38),  and  the  free  end  bears 
under  the  rear  end  of  the  rebound  lever  so  that  the  latter,  when  the 

1  Includes  escutcheons,  plain  and  threaded.    Model  should  be  stated. 


trigger  (47)  is  released  after  firing  a  shot,  carries  the  hammer  back 
to  its  safety  position  and  forces  the  trigger  forward. 

The  revolver  may  be  used  either  single  action  or  double  action. 
In  filing  double  action,  pressure  upon  the  trigger  (47)  causes  its 
upper  edge  to  engage  the  hammer  strut  (22)  and  thereby  raises  the 
hammer  (18)  until  nearly  in  the  full-cock  position,  when  the  strut 
will  escape  from  the  trigger,  and  the  hammer,  under  action  of  the 
mainspring  (32),  will  fall  and  strike  the  cartridge.  In  firing  single 
action,  the  hammer  (18)  is  first  pulled  back  with  the  thumb  until 
the  upper  edge  of  the  trigger  (47)  engages  in  the  fuU-cock  notch  in 
the  front  end  of  the  lower  part  of  the  hammer.  Pressure  on  the 
trigger  wiU  release  the  hammer  which,  under  the  action  of  the  main- 
spring (32),  will  fall  and  strike  the  cartridge.  A  projection  on  the 
upper  part  of  the  trigger,  working  in  a  slot  in  the  frame  prevents 
the  cylinder  from  making  more  than  one-sixth  of  a  revolution  at  a 
time  by  entering  one  of  the  grooves  nearest  the  rear  end  of  the  sur- 
face of  the  cyhnder.  When  the  cylinder  is  swung  out  of  the  frame 
the  slot  in  the  rear  end  of  the  crane  pivot  is  turned  so  that  the  pro- 
jection on  the  forward  part  of  the  trigger  can  not  enter  it,  which 
locks  the  trigger  and  prevents  cocking  of  the  hammer. 

The  cyhnder  bolt  (9)  is  pivoted  on  the  trigger  pin  (48),  and  its 
spring  (10),  bearing  on  the  rebound-lever  arm,  causes  the  nose  of 
the  bolt  to  project  through  a  slot  in  the  frame  ready  to  enter  one  of 
the  rectangular  cuts  in  the  surface  of  the  cyhnder.  During  the  first 
part  of  the  movement  of  the  trigger  in  cocking  the  revolver,  the 
nose  of  the  bolt  is  withdrawn  from  the  cyhnder,  permitting  free  rota- 
tion thereof.  The  object  of  the  cyhnder  bolt  is  to  prevent  rotation 
of  the  cyhnder  in  transportation,  and  its  omission  would  not  disable 
the  revolver. 

The  hand  (25)  is  attached  by  its  pivot  to  the  trigger,  and  as  the 
latter  swings  on  its  pin  when  the  hammer  is  being  cocked,  the  hand 
is  raised,  revolves  the  cylinder,  and  serves  to  lock  the  cyhnder  in 
proper  position  at  the  time  of  firing — i.  e.,  the  axis  of  the  chamber 
containing  cartridge  to  be  fired  coinciding  with  the  axis  of  the  bore 
of  the  barrel.  The  hand  spring  (26)  insures  the  engagement  of  the 
hand  with  the  ratchet.  An  abutment  on  the  side  plate  supports 
the  hand  spring  in  rear. 

The  locking  lever  (30)  is  pivoted  by  its  screw  (31)  in  the  left  side 
of  the  frame,  and  its  head  enters  a  recess  in  the  latch  (27),  so  that 
its  lower  end,  when  the  latch  is  pushed  to  the  rear,  moves  forward 
imtil  it  is  immediately  over  that  part  of  the  pivot  of  the  hand  (25) 
projecting  on  the  left  side  of  the  trigger  (47).  The  trigger  is  thereby 
locked,  and  it  is  impossible  to  cock  the  hammer  until  the  cylinder  is 
positively  closed  and  locked  by  the  latch. 


8 

The  cylinder  (8)  has  six  chambers.  It  revolves  around  and  is 
supported  on  a  central  arbor  of  the  crane  (4).  The  crane  fits  into  a 
recess  in  the  frame  below  the  barrel  and  turns  on  its  pivot  arm, 
which  rotates  in  a  hole  in  that  part  of  the  frame  below  the  opening 
for  the  cylinder,  and  is  secured  by  the  crane  lock  (6)  and  crane-lock 
screw  (7).  The  ejector  rod  (12)  passes  through  the  center  of  the 
arbor  of  the  crane  supporting  the  cylinder,  and,  projecting  under  the 
barrel,  is  terminated  by  the  ejector-rod  head  (13).  The  ejector  (11), 
of  which  the  ratchet  forms  a  part,  is  screwed  on  the  rear  end  of  the 
ejector  rod  with  a  left-handed  thread  and  then  firmly  secured  by 
upsetting  the  metal.  The  ejector  spring  (14)  is  coiled  around  the 
ejector  rod  within  the  cylinder  arbor  of  the  crane,  the  front  end 
bearing  on  a  shoulder  of  the  rod  and  the  rear  end  on  the  crane  bush- 
ing (5),  which  is  screwed  with  a  left-handed  thread  into  and  closes 
the  cylinder  arbor. 

The  thumb  piece  of  the  latch  (27)  slides  longitudinally  on  the  left 
side  of  the  frame,  and  the  barrel  of  the  latch  works  in  a  hole  in  the 
frame.  The  latch  spring  (29)  is  coiled  inside  of  the  barrel  of  the 
latch,  and  is  retained  therein  by  the  latch  pin  (28).  The  latch  pin 
also  secures  the  latch  and  hmits  its  play.  When  the  cylinder  is 
swung  into  the  frame,  the  barrel  of  the  latch,  under  the  action  of 
the  latch  spring,  is  forced  into  a  recess  in  the  ejector  and  locks  the 
cyhnder  in  position  for  firing. 

The  recoil  plate  (39)  is  driven  into  its  recess  in  the  frame  and 
secured  therein  by  slightl}^  upsetting  the  rim. 

To  Eject  the  Shells  and  Load. 

To  eject  the  shells  and  load,  push  the  latch  to  the  rear  and  swing 
the  cylinder  to  the  left,  out  of  the  frame;  pressure  against  the  front 
end  of  the  ejector-rod  head  will  empty  the  chambers,  and  the  cyl- 
inder is  then  ready  to  be  loaded;  swing  the  cylinder  into  the  frame, 
taking  care  that  it  is  revolved  so  that  the  cylinder  bolt  will  enter  one 
of  the  rectangular  cuts  in  its  surface. 

To  Dismount  and  Assemble  Revolver. 

To  dismount  the  revolver,  remove  the  parts  in  the  following  order: 
(a)  Crane-lock  screw  (7)  and  crane  lock  (6) ;  (h)  crane  (4)  with  cyl- 
inder (8);  (c)  stock  screw  (46)   and  stocks  (43)   and  (44);  (d)  side 
plate  screws  (41)  and  side  plate  (40);  (e)  hand  (25)  and  hand  spring 
(26);  (/)  mainspring  (32);  (g)  hammer  (18);  (h)  rebound  lever  (34) 
(i)  rebound-lever  spring  (37);  (j)  cyhnder  bolt  (9)  and  spring  (10) 
(k)  trigger  (47);  (I)  locking-lever  screw  (31)  and  locking  lever  (30) 
(m)  latch  pin  (28)  and  then  latch  (27)  and  latch  spring  (29). 

The  crane  and  cyhnder  should  not  be  further  dismounted  or  the 
recoil  plate  removed  except  at  ordnance  depots.  The  crane  and 
cylinder  are  dismounted  as  follows:  (a)  Unscrew  ejector  (11)  from 


ejector  rod  (12),  left-handed  thread;  (b)  remove  cylinder  (8)  from 
crane  arbor;  (c)  unscrew  ejector-rod  head  (13)  from  ejector  rod  (12); 
(d)  unscrew  crane  bushing  (5),  left-handed  thread;  (e)  remove  ejector 
rod  (12)  and  spring  (14). 

To  assemble  reverse  the  above  order. 


PARTS  ISSUED  FOR  REPAIRS. 
To  Ordnance  Officers  of  Posts  and  Regiments. 

For  making  repairs  to  these  revolvers  in  the  hands  of  troops  in 
field  and  garrison  the  following  spare  parts  are  issued  to  ordnance 
officers  of  posts  and  regiments.  The  number  opposite  each  part  is 
the  maximum  for  100  revolvers,  which  has  by  experience  been  found 
necessary  for  ordinary  repairs  per  year.  Kepairs  involving  the 
replacement  of  parts  other  than  these  can  only  be  properly  made  at 
depots  by  expert  workmen  with  the  proper  tools. 

In  making  requisition  for  spare  parts,  it  is  imperative  that  the 
model  or  models  for  which  the  parts  are  required  be  stated. 


Name  of  component  parts. 


Crane  lock 

Crane-lock  screw 

Cylinder  bolt  with  spring,  assembled 

Cylinder-bolt  spring 

Ejector-rod  head 

Hammer  with  strut,  strut  pin,  and  strut  spring 

assembled 

Hammer  stirrup 

Hammer-sfirrup  pin 

Hammer-strut  spring 

Hand  spring 

Latch  pin 

Latch  spring 

Locking  lever 

Locking-lever  screw 

Mainspring 

Mainspring  tension  screw 

Rebound  lever 

Rebound-lever  spring 

Rebound-lever-spring  pin 

Side-plate  screw 

Stock,  right  i  (model  of  1901  or  model  of  1903) 

Stock,  left  1  (model  of  1901  or  model  of  1903) 

Stock  screw 

Trigger  (includes  rebound-lever  arm  pin) 

Appendage :  Screw  driver 


Number. 


1  Includes  escutcheons,  plain  and  threaded.    Model  should  be  stated. 

To  Ordnance  Depots. 

In  addition  to  the  above,  the  following  parts  and  special  gauges 
and  tools  are  issued  to  ordnance  depots : 


Crane  bushing. 

Cylinder  and  ejector,  assembled. 
Ejector  rod . 
Ejector  spring. 
Hammer  pin. 

Hand  and  spring,  assembled. 
Gauge  for  space  between  cylinder  and 
barrel. 


Punch  and  set  for  replacing  recoil  plates. 
Range  rod  for  testing  alignment  of  the 

barrel  and  chambers  of  cylinder. 
Rebound-lever  pin. 
Recoil  plate. 
Stock  pin. 
Trigger  pin. 


10 

In  replacing  a  hand  in  a  revolver,  it  is  important  that  it  be  so 
adjusted  that  the  upward  movement  of  the  hand  will  not  begin 
to  revolve  the  cylinder  before  the  trigger  withdraws  the  cylinder 
bolt.  To  insure  this  it  may  be  necessary  to  file  the  hand  shghtly 
at  the  end  which  first  engages  the  ratchet,  and  as  this  may  bring 
the  two  points  of  the  hand  which  engage  the  teeth  of  the  ratchet 
too  near  together,  the  lower  projection  may  also  have  to  be  slightly 
filed.  The  length  and  thickness  of  this  lower  projection  must  be 
adjusted  so  as  to  bring  the  cylinder  in  proper  position  for  firing.  This 
can  be  done  only  by  expert  workmen  at  a  factory. 

PARTS  NOT  ISSUED. 

The  following  parts  are  not  issued : 

Barrel.  Frame. 

Crane.  Latch. 

Cylinder  without  ejector  and  ejector  rod.  Side  plate. 

Ejector  without  cylinder.  Sight. 

In  the  case  of  breakage  or  injury,  disabling  the  revolver,  to  parts 
other  than  those  that  may  be  issued  for  repairs  as  designated,  either 
separately  or  assembled,  th-e  revolver  must  be  returned  to  an  arsenal 
for  repairs. 

IMPORTANT  POINTS. 

(1)  The  revolver  should  he  Icept  clean,  free  from  rust,  and  properly 
oiled.  The  oil  should  nx)t  he  used  in  excess.  Waste  oil  left  in  the 
mechanism  wiU  cause  the  parts  to  gum  and  worlc  stiffly. 

(2)  The  tension  screw  should  never  he  screwed  in  tighUy  unless 
the  mainspring  fails  to  explode  the  primer,  and  if  screwed  in  too  much 
pierced  primers  will  result,  and  the  pull,  especially  on  the  double-action, 
he  greatly  increased. 

(3)  The  loclc  mechanism  must  nx)t  he  tampered  with.  The  side  plate 
should  not  he  removed  except  under  the  supervision  of  a  noncommis- 
sioned officer. 

(4)  Never  attempt  to  remove  the  side  plate  hy  prying  it  out  of  place. 
It  should  he  jarred  out  of  place  hy  smart  hlows  struclc  with  a  piece  of 
wood  on  the  left  side  of  the  frame  where  it  is  covered  hy  the  stock. 

(5)  The  side  plate  must  he  replaced  from  the  rear  so  as  to  put  its 
pin  in  rear  of  the  hand  spring.  If  this  pin  he  placed  in  front  of  the 
hand  spring,  the  spring  wiU  he  destroyed  upon  cocking  the  hammer. 

(6)  The  cran£  and  cylinder  must  not  he  dismounted  unless  suitable 
tools  are  available. 

(7)  Never  attempt  to  open  the  cylinder  when  the  hammer  is  cocked. 

(8)  Never  attempt  to  cock  the  hammer  until  the  cylinder  is  fuUy 
closed  and  locked  in  the  frame. 


11 

DIMENSIONS. 

^  .  ,  .  /pounds..     2 

W«'g" lounce...    1 

Total  length inches. .  11. 5 

Barrel: 

Length do 6 

,       ^^  /models  1894,  1896,  and  1901 do 363 

Diameter  of  bore-. |^^^^j^gQ3 ^^ 35^ 

Rifling,  number  of  grooves 6 

Grooves: 

Width inches. .      .  156 

Depth do 003 

Twist,  one  turn  in do 16 

Lands,  width do 03406 

Cylinder: 

Length do ... .     1. 499 

Diameter do 1.  52 

Chambers: 

Number 6 

Diameter inches. .      .  3825 

Front  sight,  height  above  axis  of  bore do 6045 

EXTERIOR  BALLISTICS. 
1.  Rapidity  op  Fire. 

This  pistol  can  be  fired  18  times  in  44  seconds,  loading  each  chamber 
separately,  and  beginning  and  ending  with  cylinder  closed  and  cham- 
bers empty.  Using  the  'loading  pack"  furnished  by  the  Colt's 
Patent  Fire  Arms  Manufacturing  Co.,  18  shots  have  been  fired  in  29 
seconds,  beginning  and  ending  as  above  stated.  This  was  firing 
without  aim. 

Aiming  at  25  yards'  distance,  at  a  figure  slightly  smaller  than  that 
of  an  average  man  and  using  the  pistol  as  a  self-cocker,  the  chambers 
being  loaded  separately,  18  shots  have  been  fired  in  1  minute  and  24 
seconds,  giving  13  hits.  Using  the  pistol  as  a  ''single-action" 
weapon  the  same  number  of  hits  in  18  shots  have  been  obtained  in  1 
minute  and  27  seconds. 

Aiming  at  the  same  figure,  and  at  the  same  distance  with  the 
loading  pack,  16  hits  out  of  18  shots  have  been  made  in  1  minute, 
using  the  pistol  as  a  self-cocker,  and  in  1  minute  and  25  seconds  as  a 
"single-action"  weapon. 

2.  Accuracy. 


Deviations. 

25  3'ards. 

50  yards. 

75  yards. 

100  yards. 

150  yards. 

200  yards. 

Mean  horizontal. 

Mean  vertical 

Mean  radial 

Inch. 

0.668 

.515 

;        .903 

Inches. 
0.604 
1.400 
1.553 

Inches, 
2.278 
1.612 
2.884 

Inches. 
2.400 
1.994 
3.656 

Inches. 
2.762 
7.296 

'  8. 018 

Inches. 
4.600 
6.990 
9.255 

3. 

Drift. 

The  drift  or  deviation  due  to  the  rifling  is,  in  this  arm,  to  the  left, 
but  is  more  than  neutralized  by  the  puU  of  the  trigger  when  the  pistol 


is  fired  from  the  right  hand. 


12 


Careful  firings  jnade  with  a  pistol  with  right-hand,  and  one  with 
left-hand  rifling  of  the  service  pitch,  the  weapons  being  carefully 
sighted  and  clamped  in  a  fixed  rest,  gave  the  following  as  the  drift : 


At  25  yards. 

At  50  yards. 

At  75  yards. 

At  100  yards. 

At  150  yards. 

Inch. 
0.75 

Inches. 
1.09 

Inches. 
1.57 

Inches. 
2.24 

Inches. 
7.80 

The  result  of  these  firings  indicated  that  but  little  reliance  could 
be  placed  on  results  obtained  at  over  75  yards.  A  very  slight  varia- 
tion in  the  ammunition  produced  such  widely  varying  results  at  the 
longer  ranges  as  to  render  even  an  average  of  many  results  unreliable 

and  misleading. 

4.  Recoil. 


Weight  of 
revolver. 

Weight  of          Weight  of 
powder  charge.  |        ball. 

Recoil 
(theoretical). 

Pounds. 
2.06 

Orains.              Grains. 
16                      150 

Foot-pounds. 
1. 998 

5.  Penetration  in  White  Pine. 


Range  in  yards. 

25 

50 

75 

100 

150 

200 

Depth  in  inches 

4.97 

4.35 

4.26 

3.64 

3.05 

2.90 

A  penetration  of  1  inch  in  white  pine  corresponds  to  a  dangerous 

wound. 

6.  Velocity. 

The  muzzle  velocity  of  this  weapon  with  the  Frankford  Arsenal 
cartridge,  with  about  3i  grains  of  smokeless  powder  and  148-grain 
bullet,  is  750  feet  per  second.  The  instrumental  velocity  was  ob- 
tained by  means  of  the  Le  Bouleng6  chronograph,  taking  a  mean 
of  20  shots.  The  remaining  velocities  at  the  various  ranges  were 
calculated  by  t^e  aid  of  the  formulae  and  tables  in  Ingalls's  Hand-^ 
book  of  Problems  in  Direct  Fire. 


remaining 

VELOCITY. 

At  25 
yards. 

At  50 
yards. 

At  75 
yards. 

At  100 
yards. 

At  125 
yards. 

At  150 
yards. 

At  175 
yards. 

At  200 
yards. 

Ft.  sec. 
689.9 

Ft.  sec. 
671.9 

Ft.  sec. 
654.5 

Ft.  sec. 
637.5 

Ft.  sec. 
620.9 

Ft.  sec. 
604.8 

Ft.  sec. 
589.09 

Ft.  sec. 
573.8 

7.  Force 

OP  Impact. 

At  25 
yards. 

At  50 
yards. 

At  75 
yards. 

At  100 
yards. 

At  125 
yards. 

At  150 
yards. 

At  175 
yards. 

At  200 
3rards. 

Ft.  lbs. 
155.2 

Ft.lbs. 
147.2 

Ft.lbs. 
139.7 

Ft.  lbs. 
132.5 

Ft.  lbs. 
125.7 

Ft.  lbs. 
119.3 

Ft.lbs. 
113.2 

Ft.  lbs. 
107.4 

13 

8.  Dangerous  Space. 

The  following  tables  show  the  dangerous  space  for  this  arm,  at 
ranges  from  25  to  200  yards,  under  the  varying  conditions  of  the 
weapon  being  used  by  both  mounted  and  foot  troops  and  against 
each  of  these: 

The  height  of  a  mounted  man  is,  as  usual  in  determinations  of 
dangerous  spaces,  taken  to  be  96  inches,  and  the  height  of  a  foot 
soldier  68  inches.  The  weapon  is  supposed  to  be  fired  from  the 
height  of  the  eye,  or  92  inches  for  a  momited  man  and  64  inches 
for  a  foot  soldier.  The  points  aimed  at  with  mounted  and  foot 
soldiers,  respectively,  are  84  and  34  inches  from  the  ground. 

The  determination  of  dangerous  spaces  was  made  by  filling  the 
revolver  from  a  fixed  rest,  thi'ough  screens,  and  by  means  of  the 
holes  made  by  the  bullet  determining  the  actual  trajectory.  A 
number  of  these  were  measured  and  the  mean  trajectory  taken. 
By  graphical  representation  the  dangerous  spaces  were  then  laid 
of!  and  measured. 

INFANTRY   AGAINST   CAVALRY. 


Distance. 

Ascending 
branch  ol 
trajectory. 

Pesrending  branch. 

Maximim 

continuous 

dangerous 

space. 

Total 

dangerous 

spare. 

Before    1  Teyond 
object.    1    object. 

Yards. 

25 

50 

75 
100 
150 
200 

Yards. 

Yards,   i     Yards. 
All    I      ."ifi-K 

Yards. 
81.8 
113.2 
132.4 
152.5 
201.0 
125.  S 

Yards. 
81.8 
113.  2 
132.4 
152.5 
201.0 
150.0 

All 
All 
All 
All 

80.  S 

63.2 
57.4 
52.5 
51.0 
45.0 

24.2 

INFANTRY   AGAINST  INFANTRY. 


25 
50 
75 
100 
150 
200 

All 
AM 
AU 
All 
49.2 
43.1 

25.6 

49.3 

39.9 

34.  75 

34.6 

30.6 

50.6 
93.3 
114.9 
134.  75 
83.8 
73.7 

12.25 
7.0 

50.6 
99.3 
114.9 
134.  75 
96.05 
80.7 


CAVALRY  AGAINST  INFANTRY. 


25 
50 
75 
100 
150 
200 



14.2 

27.8 
39.4 
43.4 
36.9 
35.5 


13.8 

27.0 

24.25 

52.05 

27.3 

66.7 

27.0 

07.4 

28.9 

85.8 

27.2 

62.7 

27.0 

52.05 

66.7 

67.1 

65.8 

62.7 


CAVALRY  AGAINST  CAVALRY. 


25. 

All 

All 

25.0 

50.0 

50.0 

60 

A 11 

All 

40.2 

90.2 

90.2 

75 

All 

All 

42.0 

117.0 

117.0 

100 

All 

All 

41.2 

141.2 

141.2 

150 

27.5 

80 

40.3 

120.3 

147.  8 

200 

8.0 

,-9 

:i9.8 

98.8 

106.8 

14 

AMMUNITION  FOR  COLT'S  DOUBLE-ACTION  REVOLVER,    CALIBER  .38. 

Ball  Cartridge. 
(Plate  IV.) 

This  consists  of  a  cylindrical  brass  case  containing  a  suitable 
charge  of  smokeless  powder,  an  exterior  primer  containing  0.3 
grain  of  igniting  composition,  and  a  lubricated  lead  bullet  weighing 
148  grains. 

Primer. 

The  primer  consists  of  a  cup  which  contains  the  primer  compo- 
sition (a),  and  an  anvil  (b)  for  resisting  the  blow^  of  the  firing  pin. 
The  anvil'  is  pierced  with  two  vents,  by  which  the  flame  is  com- 
municated to  the  charge.  Ignition  is  produced  by  crushing  the 
composition  between  the  cup  and  anvil  by  blow  of  firing  pin. 

Powder. 

The  powder  at  present  used  is  a  nitroglycerin  sporting  powder 
similar  to  that  used  in  shotguns.  The  charge  varies  with  the  kind 
and  lot.     At  present  about  3 J  grains  are  used. 

Bullet. 

The  form  of  the  bullet  is  a  cyhnder  surmoimted  by  a  conical 
frustum,  which  is  surmounted  by  a  spherical  segment.  Two  rectan- 
gular cannelures  contain  the  lubricant.  There  is  a  dished  cavity  in 
the  base,  by  which  the  bullet  is  brought  to  proper  weight  without 
change  of  exterior  lorm. 

Inches. 

Length  of  bullet 0. 72 

Diameter  of  cylindrical  part  of  bullet 357 

Total  length  of  cartridge 1. 362 

Lubricant. 

The  lubricant  is  Japan  wax.     The  bullet  enters  the  case  beyond 

the  cannelures   to   entirely  cover  and  protect  the  lubricant.     To 

render  the  cartridge  waterproof  the  case  is  tightly  crimped  around 

the  bullet. 

Packing. 

The  cartridges  are  packed  in  pasteboard  boxes  containing  20  c^ar- 
tridges  each.  One  hundred  pasteboard  boxes,  or  2,000  cartridges 
are  packed  in  one  zinc  case,  hermetically  sealed,  with  handle  for 
tearing  open.  The  whole  is  inclosed  in  a  wooden  box,  the  eover  of 
which  is  fastened  with  thumbscrews  and  sealed  with  wire. 

Pounds. 

Weight  of  100  cartridges 3 

Weight  of  2,000  cartridges,  packed 72 


15 

Blank  Cartridge. 

This  cartridge  has  the  same  case  and  primer  as  the  ball  cartridge. 
There  is  no  bullet.  A  charge  of  7  grains  of  E.  C.  powder  is  pressed 
in  the  case  and  held  there  by  crimping  the  case  over  a  cup  of  shellacked 
paper. 

These  cartridges  are  packed  in  a  manner  similar  to  the  ball  car- 
tridges. The  packing-box  cover  has  not  the  quick-opening  thimib- 
screw  fastening.  A  box  of  2,000  blank  cartridges  packed  weighs 
30  pounds. 

War  Department, 

Office  op  the  Chief  op  Ordnance, 
Washington,  June  19,  1917. 

April  1, 1908. 
Revised  October  3, 1908. 
.  Revised  June  19, 1917. 
26791-J-35. 
33735-20&-1. 
Form  No.  1919. 
Ed.  June  19-17—10,000. 


PLATE   IV. 


38  CAL/B£R  R^VOLV£R  CARTR/D6E3, 


^_      /.02SMAX. 
/.O/S  MfN  . 


/.3 67  MAX. 


/.357M/A/. 


BALL   CA^TR/OGE, 


3H£LLAC 
PAPER  CUP 


/.O/S  M/W. 
BLANK    CA/?T/?/DG£  . 


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